Ewing sarcoma - Foot and Ankle

Summary
Description

Ewing's sarcoma occurs in every bone of the foot. About one-third are located in the hindfoot, and 20% of the total occur in the calcaneous.

People and Age
The mean age at diagnosis of patients with tumors in the foot is 17 years.
Symptoms and Presentation
Patients normally have pain accompanied by significant diffuse swelling.
Brief description of the xray
The radiologic appearance of Ewing's sarcoma in the foot is highly variable
Brief desc of tx
Treatment consists of chemotherapy, radiation therapy, and surgical resection depending on stage and extent of disease.
Tumor Name
ewing sarcoma - foot and ankle
Tumor Type
Tumors of the Foot and Ankle
Benign or Malignant
Malignant
Body region
ankle and foot, leg
Most Common Bones
calcaneus
Location in bone
diaphyseal
metaphyseal
Position within the bone
central
Tumor density
lytic
Complete Information on this Tumor
Introduction and Definition

Ewing's sarcoma occurs in every bone of the foot. About one-third are located in the hindfoot, and 20% of the total occur in the calcaneous. Ewing's of the foot is a highly aggressive tumor with frequent metastasis. A complete cancer staging work-up is required and a carefully planned biopsy should be the last step in the sequence.

Incidence and Demographics
The mean age at diagnosis of patients with tumors in the foot is 17 years.
Symptoms and Presentation

Patients normally have pain accompanied by significant diffuse swelling. The area may appear inflamed and a misdiagnosis of infection can be made. The white blood cell count, erythrocyte sedimentation rate and temperature may all be moderately elevated.

Patients have symptoms for an average of 14 months prior to diagnosis. Patients with hindfoot lesions have an average duration of symptoms of 22 months prior to diagnosis, whereas those with forefoot lesions have an average duration of symptoms of seven months.

X-Ray Appearance and Advanced Imaging Findings
The radiologic appearance of Ewing's sarcoma in the foot is highly variable. The tumor may present as a small lytic lesion with a permeative appearance and no matrix or soft tissue calcification. In other cases the lesion causes permeative lysis accompanied by marked sclerosis. In an unusual case involving the distal fibula, the lesion appeared entirely cystic and was mistaken for a unicameral (simple) bone cyst.

Bone scan shows abnormal uptake, which may be intense. CT scan demonstrates the permeative destruction well. MRI is essential for surgical planning and demonstrates the soft tissue extent of the mass, which may be characteristically extensive.
Treatment Options for this Tumor
Treatment consists of chemotherapy, radiation therapy, and surgical resection depending on stage and extent of disease. Ewing's sarcoma in the foot (see the images of the case at right) with regional metastasis can be treated with radiation of the primary, resection and radiation for the metastasis plus chemotherapy in order to balance the positive and negative effects of treatment in the setting of a relatively poor prognosis.
Outcomes of Treatment and Prognosis
Survival is highly dependant on the stage of the disease and may also vary according to location. Patients without metastasis had 88% survival, whereas those with non-pulmonary and pulmonary metastasis had 10% and 0% survival, respectively. Patients with tumors in the forefoot had 70% survival and those with tumors in the hindfoot had 33% survival. Tumor size and delay before diagnosis also vary by site, and these factors are likely to have a greater impact on prognosis than the difference in site alone.